Uninstall the Alexa app on your mobile device as well as any Alexa things in OH. Then reinstall Alexa app, go thru the authentication steps again and rediscover the Thing in OH.
That is the problem - I cant uninstall the alexa things. All the things of alexa come across with the confilct 409 error.
Do you have Things created in files as well as PaperUI? If so, comment out the things file as well as any items relating to Alexa things.